Miscarriage causes

If you are pregnant, you may be concerned about the risks of miscarriage or pregnancy loss. In most cases, this happens for reasons that you have no control over. In fact, it is often difficult to determine the exact cause. Learning why this happens can help you feel more confident and increase your chances of having a healthy full-term pregnancy.

Here is an overview of some of the most common causes of miscarriage.

Abnormal chromosomes

If a miscarriage occurs in the first 12 weeks, more than half of the time it is due to problems with the baby's chromosomes. Chromosomes contain genes that determine your child's unique traits, such as hair and eye color. A child cannot grow normally with an incorrect number of chromosomes or damaged chromosomes.

An abnormality in the chromosomes of an unborn child can cause one of many problems. Among the most common:

Blighted ovum. The embryo does not develop.
Molar pregnancy. Both sets of chromosomes come from the father, but neither set comes from the mother. The placenta does not develop normally and the fetus does not develop.
Partial molar pregnancy. The father donates two sets of chromosomes in addition to the mother's. The embryo may begin to develop, but quickly stops.

Several other chromosomal abnormalities can cause pregnancy loss. These include trisomy 13, trisomy 18, trisomy 21 (Down syndrome), monosomy (Turner syndrome), and other problems with the sex chromosomes.

Here are a few more things to remember about abnormal chromosomes:

Chromosomal problems cannot be prevented.
With age, especially after 35 years, the risk of chromosomal problems and miscarriage in general increases.
Miscarriages due to chromosomal problems do not usually recur in future pregnancies.

Medical conditions

Pregnancy loss is often the result of maternal health problems. Some of them include:

An infection such as cytomegalovirus or rubella
Poorly controlled long-term diseases such as diabetes or high blood pressure
Thyroid disease, lupus, and other autoimmune disorders
Problems with your uterus or cervix, such as fibroids, an abnormally shaped uterus, or a cervix that opens and widens too early, called cervical insufficiency
Sexually transmitted diseases infections such as chlamydia, gonorrhea, syphilis, or HIV
Blood clotting issues that block blood vessels carrying blood flow to the placenta
Lifestyle

Your habits of the expectant mother may increase the risk of miscarriage. Here are some dangerous habits for a developing child:

Smoking. Some studies show an increased risk of pregnancy even if only the father smokes.
Excessive alcohol consumption
Illicit drug use

Environmental hazards

In addition to secondhand smoke, certain substances in your environment at home or at work can jeopardize your pregnancy. This includes:

Mercury released from broken thermometers or fluorescent light bulbs
Solvents such as paint thinners, degreasers, and stain and varnish removers
Pesticides for killing insects or rodents
Arsenic found near waste sites or in some well water

Be sure to discuss this with your doctor. You may find that your risks are not as great as you think.

Medications

Certain prescription and over-the-counter medicines can increase the risk of miscarriage and pregnancy loss, including:

Misoprostol. It is used for conditions such as peptic ulcers and rheumatoid arthritis.
Methotrexate, a drug for rheumatoid arthritis
Retinoids. They are used for skin conditions such as eczema and acne.
Non-steroidal anti-inflammatory drugs for pain and inflammation

Food poisoning

Certain types of food poisoning during pregnancy can increase the risk of miscarriage or miscarriage.

Listeriosis. Commonly found in unpasteurized soft cheeses such as blue, brie, or queso fresco, and raw or undercooked seafood.
Salmonella. Commonly found in raw or undercooked eggs
Toxoplasmosis. It is most commonly caused by eating infected raw meat.

Some food poisonings, including listeriosis and toxoplasmosis, can infect your unborn baby even if you don't have symptoms yourself.

Follow your doctor's recommendations for cooking and foods to avoid during pregnancy.

What doesn't cause a miscarriage?

You may be concerned that certain activities or emotions increase your risk of pregnancy. But unless your pregnancy is considered high risk, the following things are generally safe:

Working
Sitting or standing for reasonable amounts of time
Exercise
Having sex
Air travel
Eating spicy food
Having an emotional shock or scare
Stress or depression

Prevention of miscarriage

While there is no surefire way to prevent miscarriage or pregnancy loss, there are steps you can take to ensure a healthy pregnancy:

Get tested before conception.
Visit your prenatal period regularly so your doctor can help prevent and treat any problems early. Make addressing existing health problems a priority. Your efforts will give your child the best chance of health.
Combat dangerous lifestyle habits. If you can't quit smoking on your own, talk to your doctor for help to quit smoking.
Ask your doctor about your environmental risk and how to protect yourself.
Ask your doctor if you should see a specialist obstetrician, such as a perinatologist, especially if you have had more than one miscarriage. These doctors specialize in difficult pregnancies.
Take a daily multivitamin.
Limit caffeine.
Have a healthy and balanced diet.
Avoid certain foods that can carry bacteria.
Maintain a healthy weight.

Know that you can do everything “right” and still have a miscarriage. Try not to add guilt or feelings of guilt to your emotional burden. Between working with your doctor and making changes to your healthy lifestyle, you can rest easy knowing you've done your best for a healthy pregnancy.